A probable cephalopod eggs as epibionts on Mastigograptus
Clistrocystis graptolithofilius, known from
Ordovician glacial boulders from Poland, was
described by
R. Kozłowski (1959) as an
enigmatic organic fossil. These distinctive
forms were epibionts on
Mastigograptus
colonies.
  
   Later,
R. Kozłowski (1965)
reinterpreted
Clistrocystis as probable
cephalopod egg capsules, laid down on
graptolite stipes.
          ________________________

A. Ordovician Clistrocystis graptolithofilius
on
Mastigograptus stipe.

B. Egg capsules of Recent Sepia officinalis
on the seagrass
Zostera.
                                             
Based on:

Kozłowski, R. 1959. Un microfossile enigmatique. -
Acta Palaeontologica Polonica 4, 273-277.
Kozłowski, R. 1965. Oeufs fossiles des Cephalopodes? -
Acta Palaeontologica Polonica 10, 3-9.